Circuit board designs utilize various arrangements in an effort to improve thermal radiation of heat from the chip while reducing thermal resistance. These designs often attempt to release heat to the motherboard through numerous thermal through holes or vias formed in the laminate circuit board. Thermally conductive material is place in the through holes and attached to the chip. Balls of solder are attached to the opposite end of the thermally conductive material and heated such that the solder adheres to the motherboard thereby forming a conductive path for heat to flow from the chip to the motherboard. These through hole designs can be very complicated due to the large number and small size of the through holes.
Some circuit board configurations having built-in heat spreaders in the plastic mold portion of the board, called Thermally Enhanced—Enhanced Plastic Ball Grid Array or TE-EPBGA, have also been used. These configurations utilize wire bond packages having wires (often made of gold, Au) that extend out from around the die to the laminate board. Thus, even if a heatslug or dissipater is used with this configuration, the wires effectively limit the size of the heatslug to the size of the die. Resin is also used to fill in between the die and heatslug, thereby increasing thermal resistance.
There also exists a circuit board configuration having a heat spreader installed on the laminate surface and a chip attached, referred to as a High Performance Ball Grid Array or HPBGA. This configuration has good thermal radiation. However, the laminate and BGA process is complicated and very expensive.